9.8 seek ¶

off_t seek(int fd, off_t offset, int whence);

This syscall repositions the file offset of the passed file description to the passed offset according to the directive whence as follows:

• SEEK_SET (1): Set to the passed offset.

  SEEK_CUR (2): Set to the current offset plus the passed offset.

  SEEK_END (4): Set to the size of the file plus the passed offset.

This syscall returns the resulting offset, or -1 on failure. errno is to be set to:

• EBADF: Bad file descriptor.
• EINVAL: The whence is malformed or the resulting offset would be invalid.
• ESPIPE: seek was called on a TTY or a pipe.